The bradykinin BK2 receptor mediates angiotensin II receptor type 2 stimulated rat duodenal mucosal alkaline secretion.

• BACKGROUND: This study investigates bradykinin and nitric oxide as potential mediators of AT2-receptor-stimulated duodenal mucosal alkaline secretion. Duodenal mucosal alkaline secretion was measured in methohexital- and alpha-chloralose-anaesthetised rats by means of in situ pH-stat titration. Immunohistochemistry and Western blot were used to identify the BK2 receptors. RESULTS: The AT2 receptor agonist CGP42112A (0.1 microg kg(-1) min(-1)) administered intravenously increased the duodenal mucosal alkaline secretion by approximately 50 %. This increase was sensitive to the selective BK2 receptor blocker HOE140 (100 ng/kg i.v.), but not to luminal administration of the NOS blocker L-NAME (0.3 mM). Mean arterial pressure did not differ between groups during the procedures. Immunohistochemistry showed a distinct staining of the crypt epithelium and a moderate staining of basal cytoplasm in villus enterocytes. CONCLUSION: The results suggest that the AT2-receptor-stimulated alkaline secretion is mediated via BK2 receptors located in the duodenal cryptal mucosal epithelium.

Nyckelord

Animals

Blood Pressure

physiology

Duodenum

blood supply

chemistry

physiology

secretion

Fasting

physiology

Hydrogen-Ion Concentration

Intestinal Mucosa

blood supply

chemistry

physiology

secretion

Intestinal Secretions

chemistry

physiology

Male

Rats

Rats

Sprague-Dawley

Receptor

Angiotensin

Type 2

physiology

Receptor

Bradykinin B2

metabolism

physiology

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)